This application claims the priority of German Patent Document 199 62 950.1, filed in Germany, Dec. 24, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to a rollover protection system for motor vehicles of the type having a head restraint assigned to a vehicle seat and a rollover member displaceable from a lowered inoperative position to an upper support position.
In the event of an accident in which the vehicle overturns, there is, especially on open-top motor vehicles such as convertibles, off-road vehicles etc., no protective, bracing roof structure as there is in enclosed vehicles. Rollover protection systems are therefore intended to help protect the occupants of open-top motor vehicles against injury in the event of overturning.
On some known, existing open-top vehicles the windscreen frame and a fixed bar, which extends over the vehicle behind the (rear) seats, serve as rollover protection. Since such a fixed rollover bar may detract from the overall visual appearance of the vehicle there are, for classic convertibles without these fixed rollover bars, lowerable bars in the rear compartment of the vehicle. Should the vehicle overturn, this rollover bar is automatically swivelled about an axis from an inoperative position into its operative position.
Another rollover protection system is described in German Patent Document DE 39 27 265 C2 (corresponding U.S. Pat. No. 5,205,585). This relates to a rollover protection system in which a rollover bar can be shifted into its ultimate deployed position by means of flexible pre-stressing devices in response to a signal triggered in the event of overturning, the movement of the rollover bar occurring substantially in one plane that runs perpendicular to the longitudinal axis of the vehicle. At least one padded cushion serving as head restraint is also provided on the said rollover bar. The rollover bar can also be shifted into the deployed or lowered ultimate position by an additional drive, by means of which the height of the head restraint can be correspondingly adjusted to suit the respective occupant in the associated seats.
A rollover protection system in which a rollover bar combined with a head restraint is assigned to each vehicle seat, the rollover bar behind the associated seat being braced on the vehicle floor behind the associated seat and its legs being height-adjustable in guides, and the U-shaped frame serving to fix the consequently vertically moveable head-restraint padded cushion, is described in German Patent Document DE 38 22 461 C2.
In this known rollover protection system, the fact that the entire rollover bar always has to be moved when adjusting the head restraint and the means of clamping also have to be released and clamped each time has proved to be a disadvantage. This means that the means of clamping must be designed using very high-grade and hence costly materials. Furthermore, adjusting the entire rollover bar in order to adjust the head restraint makes a very expensive drive mechanism necessary.
German Patent Document DE 39 22 509 C2 (corresponding U.S. Pat. No. 5,056,816) discloses a rollover bar, which spans the width of the passenger compartment of the vehicle and the legs of which are displaceable in guide tubes fixed to the vehicle. At the same time the rollover bar is arranged behind the vehicle seat backrests. Such a construction has proved disadvantageous, since the rollover bar must be specifically accommodated in the vehicle and braced in relation thereto. Furthermore, such a rollover bar takes up a considerable separate amount of space in the passenger compartment of the motor vehicle EP 0 407 741 A1 (corresponding U.S. Pat. No. 5,056,816) and EP 0 439 565 B1 (corresponding U.S. Pat. No. 5,205,585) furthermore disclose the fitting of an additional padded cushion, which serves as head restraint, to the top section of the rollover bar. Even these rollover bars, however, have the disadvantage that in order to adjust the head restraint to suit the respective occupants the entire rollover bar always has to moved, thereby necessitating the use of costly materials and an expensive drive mechanism, as already described above.
In addition, rollover protection systems are disclosed in German Patent Document DE 39 30 171 C2 (corresponding U.S. Pat. No. 5,110,185) and European Patent Document EP 0 456 646 B1 (corresponding U.S. Pat. No. 5,458,396). In these, the rollover bar is arranged in the seat backrest and in the inoperative position runs with its upper outer contour flush with the adjoining contour of the head restraint. In both cases the rollover protection member is braced in relation to the vehicle body by way of the supporting structure of the seat backrest in the event of overturning. On the one hand this saves overall space, since not only the head restraint but also the rollover bar is incorporated into the seat backrest and does not have to be separately accommodated in the vehicle and braced in relation to the latter. On the other hand, however, the seat itself on the adjusting rails, the adjusting joints and motors and the support structure entail a considerable cost.
A further rollover protection system for an automobile is disclosed in European Patent Document EP 0 850 808 B1 (corresponding U.S. Pat. No. 5,927,803). In this case a rollover bar is designed with a head restraint assigned to a vehicle seat and is displaceable by an at least approximately translational movement from a lowered inoperative position upwards into a support position. In this case the rollover bar in the inoperative position is incorporated with its upper section into the head restraint of the vehicle seat. The head restraint furthermore has a receiver, in which, in the inoperative position, the upper section of the rollover bar is accommodated. If the rollover bar is now to deploy to its maximum possible bracing height, a part of the head restraint folds upwards in the manner of a cover, and in the event of overturning the rollover bar can deploy through this opening.
The fact that the head restraint remains in its original position and that the occupants of the corresponding seats may thereby be at risk from the free-standing rollover bar in the head impact area, however, has proved something of a problem in this case. Moreover, a thin padded cushion on the rollover bar only affords the occupants inadequate protection against an impact with the rollover bar.
In the event of an accident occupants may also possibly strike the deployed rollover bar on the opposite side of the vehicle, thereby sustaining injuries.
Proceeding from this known prior art, an object of the invention is to provide a rollover protection system of the type mentioned at the outset, which affords the occupants better protection in the event of overturning but which is less costly to produce.
This object is met by providing a rollover protection system for motor vehicles, especially for convertibles, with a head restraint assigned to a vehicle seat and a rollover member displaceable by an at least approximately translational movement from a lowered inoperative position upwards into a support position, the head restraint having a recess open at the bottom, wherein the rollover member is accommodated with its upper section in a recess of the head restraint in both the inoperative position and the support position.
In the rollover protection system according to the invention the head restraint has a recess open at the bottom and is deployed to a maximum bracing height in the event of overturning. The rollover member is surrounded by the head restraint at all times, due to the fact that the head restraint now moves into the support position with the rollover member. As a result this affords the occupants of the vehicle the maximum possible protection to prevent them striking parts of their body against the support structure of the rollover member, so that head impact injuries, in particular, can be prevented or considerably reduced. The rollover protection system according to the invention is of particular advantage, for example, in the event of a secondary impact with the rollover member already deployed or in a situation in which the rollover member deploys whilst the head of at least one of the occupants is situated above the rollover member.
According to an especially preferred embodiment of the invention a supporting structure is incorporated into the head restraint recess. In this case the supporting structure may either be built into the head restraint, or the head restraint may also simply be flanged on to the supporting structure.
At the same time the shape of the structure is such that it has a shape corresponding to that of the rollover member. Therefore if the rollover member takes the form of a U-shaped bar, for example, the supporting structure has a shape corresponding to that of the bar.
This structure is in any case brought to maximum bracing height by the deploying rollover member in the event of overturning, the head restraint carrying it along and fixing it in this position by positively interlocking.
The positive interlock fixing preferably occurs in such a way that the rollover member is deformed in a certain way, thereby adjusting to the shape of the support structure.
The supporting structure of the head restraint therefore serves as the actual outwardly bracing part, which is itself, however, in turn braced by the rollover member.
Further advantages and embodiments of the invention emerge from the further claims and the preferred exemplary embodiments described in principle below with reference to the drawing.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.